Number Fluctuations and Energy Dissipation in Sodium Spinor Condensates

TL;DR

This paper investigates atom number and spin fluctuations in sodium spinor condensates, revealing how these fluctuations relate to energy dissipation and phase space dynamics, with a phenomenological model capturing dissipation behavior.

Contribution

It introduces a quantitative analysis of fluctuations as a measure of energy dissipation and identifies a dissipation-driven phase space crossing in sodium spinor condensates.

Findings

Fluctuations enable measuring energy dissipation.

Maximum population fluctuations indicate phase space crossing.

Dissipation depends exponentially on magnetic field and linearly on density.

Abstract

We characterize fluctuations in atom number and spin populations in F=1 sodium spinor condensates. We find that the fluctuations enable a quantitative measure of energy dissipation in the condensate. The time evolution of the population fluctuations shows a maximum. We interpret this as evidence of a dissipation-driven separatrix crossing in phase space. For a given initial state, the critical time to the separatrix crossing is found to depend exponentially on the magnetic field and linearly on condensate density. This crossing is confirmed by tracking the energy of the spinor condensate as well as by Faraday rotation spectroscopy. We also introduce a phenomenological model that describes the observed dissipation with a single coefficient.